DSE Geography | Agricultural systems and food supply: lesson-prep guide for tutors

2026-11-02

Tutor lesson-prep guides · Secondary Geography

Students see the word farm and write good weather, fertile soil, then stop. This lesson turns a farm into a system of inputs, processes and outputs that can be checked item by item.

Objectives — Students can: (1) sort farm activity into inputs, processes and outputs, splitting inputs into natural and human; (2) judge intensive versus extensive using labour per hectare, capital per hectare and yield per hectare; (3) explain why the same crop is grown in different places, and how cold chains and subsidies change that answer today.

01 Prerequisites (3-minute check)

If any of these fails, fix it before the lesson starts.

Skill	Quick check	Pass mark
Systems	What are the three basic parts of a system?	Inputs, processes, outputs, plus feedback
Climate	What limits farming in rainforest and temperate climates?	Leaching and poor nutrients; a short growing season and frost
Population	How does density affect intensity?	High density and little land per person push labour-intensive, high-yield farming

02 Lesson flow (60 minutes)

Time	Stage	Tutor does	Student does
0–5 min	Opening question	Show hand transplanting beside a combine harvester and ask which input differs most	Vote and name the input
5–15 min	Prerequisite check	Three quick checks (system parts, climate limits, density and intensity)	Written answers, marked live
15–37 min	Three-part script	Teach the three columns, intensity, and location with food supply	Recap each part in one sentence
37–49 min	Question walk-through	Model four questions, writing units beside every number	Copy and convert one figure themselves
49–55 min	Independent practice	Circulate; ask only what the unit of this number is	Do three items and self-mark
55–60 min	Exit check	Collect answers and count misses aloud	Written, no talking

03 Teaching script (read it out)

Scene 1: Part 1: three columns

Do not start with weather. Open three columns: inputs, processes, outputs. Split inputs into natural, meaning solar energy, rainfall, soil nutrients and temperature, and human, meaning labour, seed, fertiliser, machinery, capital and subsidies. Processes run in time order: ploughing, sowing, irrigation, fertilising, pest control, harvest, storage and transport. Outputs are not only crops: there are by-products, profit and environmental effects such as soil erosion and methane from paddy fields. Fill the three columns and the answer has a spine.

Is fertiliser a natural or a human input? What about rainfall?

Scene 2: Part 2: intensive and extensive, three measures

Whether a farm is intensive is not about how hard it feels. Use three numbers: labour per hectare, capital per hectare and yield per hectare. Rice in monsoon Asia has high labour and high yield, so it is labour-intensive. Wheat on the North American prairie has high machinery and little labour, so it is mechanised extensive farming. Dutch glasshouses have very high capital per hectare. Beware one trap: extensive does not mean backward, because output per worker on the prairie is far higher than on many intensive farms.

The same high yield can be intensive or extensive. Which measure separates them?

Scene 3: Part 3: location and food supply

The von Thunen model says one thing: the further from market, the higher the transport cost, so perishable crops with high rent-paying ability sit near the city, such as vegetables and fresh milk, while grain, which travels well, sits further out. Cold chains, containers and subsidies have stretched those rings rather than abolished them, because transport still costs money. Food supply is not simply about output either: global production is enough, but distribution is uneven, farmland is being lost, and extreme weather hits one region at a time. Those three together explain hunger.

Did cold chains erase the rings or bend them?

04 Question types and worked steps

Type	Example	Steps	Answer
System diagram	Fill inputs, processes and outputs for a farm case.	(1) Split natural and human inputs; (2) order processes in time; (3) give main and by-products; (4) add one environmental effect.	Example: paddy -> rainfall, labour, transplanting machine; rice, straw, methane.
Intensity comparison	Compare two farms.	(1) Labour per hectare; (2) capital per hectare; (3) yield per hectare; (4) conclude using all three.	Example: 3 workers per hectare versus 0.05 means the first is labour-intensive.
Location explanation	Explain why a crop is grown where it is.	(1) Natural factors; (2) human factors such as market distance, transport cost, labour, policy; (3) name the key one.	Example: peri-urban vegetables -> perishable, transport-sensitive, high rent-paying ability.
Food data question	Given output and population, decide whether food is enough.	(1) Output per person; (2) compare with need; (3) discuss distribution and waste; (4) then conclude.	Example: 54 tonnes for 200 people is 270 kg each, enough, yet distribution decides who eats.

Sanity check (teach this): Sanity check: the model farm is 12 hectares at 4.5 tonnes per hectare, so output is 54 tonnes, or 54,000 kg; at 6 dollars per kg revenue is 324,000 dollars; with costs of 180,000 the profit is 144,000, a margin of 44.4 per cent, or 12,000 per hectare. The commonest error is multiplying tonnes by a price per kilogram, which gives 324 dollars. Require the unit beside every line, and mark unit errors as zero.

05 Independent practice (3 questions)

Question	Answer	What to watch
Turn a 12-hectare farm yielding 4.5 tonnes per hectare into total output and revenue at 6 dollars per kg.	54 tonnes equals 54,000 kg; revenue is 324,000 dollars.	Check the tonne-to-kilogram step; skipping it is the unit error.
Decide whether that farm is intensive or extensive and name the measure you used.	Under 0.1 worker per hectare with high machinery cost is mechanised extensive; two or more workers per hectare is labour-intensive.	Check that a number and a verdict both appear; adjectives alone do not count.
Explain why dairy farms sit near cities rather than in remote uplands.	Milk is perishable and needs cold chains, so distance costs time and spoilage; remote areas suit grain or grazing.	Check that perishability and transport cost are both named.

06 Common mistakes and what to say

Mistake	Student writes	Say this
Good weather as the whole answer	Writes that the weather is good and the soil fertile, so rice grows.	Weather is one natural input. Where is the process, the labour, the market? Add three and the answer holds.
Confusing yield with productivity	Says output is high so the farm is intensive, without a denominator.	High per what? Per hectare or per worker? The two answers can point opposite ways.
Skipping the unit conversion	Multiplies 54 tonnes by 6 dollars and writes 324 dollars.	Tonnes do not multiply by a price per kilogram. Write 54 tonnes equals 54,000 kg first.
Reading extensive as backward	Writes that extensive farming is inefficient.	Extensive means little input per hectare, not low output per worker. One prairie farmer feeds hundreds.

07 Homework (paper, section and question numbers)

Secondary Geography index: finish the three exercises, then practise per-capita sums in the population and migration chapter — Exercises 1–3 on this page

08 Exit check (last 5 minutes)

Question	Answer	Decision
What are the three columns of an agricultural system?	Inputs, processes, outputs	Cannot answer: reteach part 1
Which three measures show intensity?	Labour, capital and yield per hectare	Cannot answer: reteach part 2
Why are dairy farms near cities?	Perishable, cold-chain cost, transport time	Cannot answer: reteach part 3

09 Tutor FAQ

Which year is this for?

S5 agriculture and food, and S4 classes already teaching natural systems can start here.

Must students memorise von Thunen?

They need distance, transport cost and rent, not every assumption.

Is there a matching paper?

The homework link goes to the secondary Geography index, which pairs with the population and migration chapter.

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A TutorZone lesson-prep guide. Written by the TutorZone team; questions and lesson flow are original and are not taken from any school or publisher material.